Bis(difluoromethyl) ether has been prepared previously by chlorination of dimethyl ether followed by isolation and fluorination of bis(dichloromethyl)ether. The chlorination step gave a complex mixture of chlorinated dimethyl ethers some of which were unstable, e.g. to distillation, from which bis(dichloromethyl)ether was separated. Two of the ethers in the mixture, chloromethyl methyl ether and bis(chloromethyl)ether, are potent carcinogens.
Due to the difficulty and cost in preparing dimethyl ether products which are free of carcinogens, little effort has been focused on their synthesis. This is especially true in view of the well known, commercially available alternatives, such as "FREON" "HALON" and other well known chlorofluorocarbons (CFCs) which are used as refrigerants, etc.
However, the use of CFCs has been sharply curtailed and will eventually be phased out due to their propensity to destroy the ozone layer.
The use of bis(difluoromethyl)ether has been proposed as a propellant and as a refrigerant alternative to CFCs. See U.S. Pat. Nos. 4,041,148 and 4,961,321. The known processes for forming such alternatives are too expensive, have too low a yield and generate harmful (carcinogenic) byproducts, making the development of inexpensive CFC alternatives unlikely.
There is a critical need for the discovery and commercialization of practical, economical processes for the production of alternative environmentally safe compounds to replace the CFCs.